1. Field of the Invention
The present invention relates to a wrench and, in particular, to an adjustable wrench that includes a reinforcing device for increasing its structural strength to prevent deformation of two walls of a rail of the adjustable wrench caused by improper operation or when impinged by an outside force.
2. Description of the Related Art
A conventional wrench is a tool used to provide grip and mechanical advantage in applying torque to turn objects, usually rotary fasteners, such as nuts and bolts, or to keep them from turning. One type of the wrench is called an open end wrench, which has a U-shaped opening to grip two opposite faces of the bolt or nut. This wrench is often double ended, with a different-sized opening at each end. The ends are generally oriented at an angle of around 15 degrees to the longitudinal axis of the handle. This allows a greater range of movement in enclosed spaces by flipping the wrench over. Moreover, an adjustable wrench is a wrench with a jaw of adjustable width, allowing it to be used with different sizes of fastener heads rather than just one fastener, as with a conventional open end wrench.
U.S. Pat. No. 8,136,429 discloses an adjustable wrench, which includes a handle, a head, a slidable jaw, an axial rod and a worm gear. The head is formed with a fixed jaw, a sliding rail, and a receiving slot. The slidable jaw has a sliding rod slidably disposed in the sliding rail of the head. The axial rod and the worm gear are disposed in the receiving slot of the head, and the worm gear engages with the sliding rod of the slidable jaw to control the movement of the slidable jaw in relation to the fixed jaw, so that an opening formed between the fixed and slidable jaws can be adjustable for different sizes of fastener heads. However, when the adjustable wrench turns objects, the sliding rod will push against the sliding rail to cause deformation of two walls of the sliding rail.
The present invention is, therefore, intended to obviate or at least alleviate the problems encountered in the prior art.